Quoted from MrMikeman:ummmm... not quite. Silkscreening is done in layers with dithering. I visited Stern back in the day when they were still silkscreening their own playfields and also CPR when they first started. I've seen it first hand. It takes many layers to get all the colors down and each layer has to dry before the next one is applied. Long and tedious.
From what I was told screen printing is basically an inkjet printer. I think it's 1 pass and done. Screen printing is cheaper and faster which is why most manufacturers changed to that method. Oh and you get nicer photo realistic artwork. Only problem is lifts with the clearcoat.
From a non-expert point of view is would seem like there's an adherence issue with the ink with the newer process. It sticks to the clearcoat much more than it sticks to the playfield.
Screen printing and silk screening are just different names for the same thing. In this process each layer of ink is put down separately by pushing ink through a silkscreen onto whatever media you are printing on.
Typically screen printing utilizes 4-color process (aka CMYK) which utilizes cyan, magenta, yellow and black ink to create the appearance of a limited gamut of colors. Playfields typically screened CMYK utilize six silk screens (white, C, M, Y, K and opaque black). Solvent based inks are used when silk screening playfields.
We have screen printed all remakes utilizing spot colors as was done for the original games. Utilizing spot colors provides a much wider color gamut. Instead of colors being represented by a mix of C, M, Y or K dots, the color you are seeing is achieved by mixing each ink to the specific color desired. Another upside to spot colors is a richer appearance as the solid colors tend to fully flood an area instead of appearing as small dots. The downside of spot colors is efficiency. Our previous remakes have required 12 to 14 screening operations. Each operation needs to be near perfectly registered to the previous layer of silk screen ink.
The other downside of silk screening playfields is the skill level required.
I believe the other playfield manufacturers are digitally printing playfields and sometimes digitally printing and then adding a single screen printed spot color. Digital printing equipment puts down all four colors (CMYK) in a single pass. Digital inks are UV cured which mean they dry instantly. Most digital printers are 4-color process. Registration between the colors is never an issue and loading a digital press requires almost no skill.
I believe all playfield manufacturers are using urethane clear coats. Some are using automotive grade urethanes which are widely available and less expensive. We still use the same supplier and material as Williams/Bally did. This product was initially developed to coat the heads of wooden golf clubs by a chemist named Dale Bodiker. He found a way to formulate a urethane hard coat that would remain flexible over time. We have looked for another product with similar characteristics but have been unable to find anything that remains flexible.
Urethane is extremely sensitive to certain contaminants. UV inks are typically produced by the manufacturer of the printing equipment. I have looked into digital printing equipment but have been unable to find digital inks specifically formulated for use with urethane. That doesn’t mean they don’t exist. We purchase solvent based inks mixed to our specifications which include purity level requirements.
Bakersfield, CA
Saint John, NB
